Large groups of wireless nodes attempting to communicate with each other must coordinate a channel architecture in order to communicate with certain nodes on certain channels whilst avoiding interfering with other nodes on those channels. U.S. Pat. No. 6,941,140 describes a system for avoiding interference on channels amongst a group of nodes in a centralised wireless architecture such as a cellular network. The nodes in this network are not forming communication links with any other nodes, but use uninterfered channels to communicate with handsets. Test signals are transmitted/received on different channels in order to determine channel preferences amongst nodes by inhibiting channel selection, and allow them to avoid interfering with each other. On high preference channels the transmission power is increased which further inhibits receiving nodes from using this channel. EP1074161 describes a centralised prediction mechanism which can also be used to estimate the effect of channel use on other nodes use of the channel; which may also be used as an inhibitory factor.
WO2005/029788 describes a mechanism by which a node in a decentralised (ie ad hoc) network determines a channel to use, and in which an initial high power “discovery” phase is used whereby the node listens/transmits on a channel, and if quiet reverts to a lower power setting for normal communication on that channel.
WO2005/0011203 describes a system in which groups of nodes sharing a channel can migrate to another channel, for example because of increased interference from non-group members.
US Patent application 2004/0185887 discloses a wireless network in which some nodes have two or more transceivers which can operate on different frequency channels. Each node keeps a record, for each of its neighbours, of the quality of channels to each known network interface on that neighbour. A channel is then selected for communication with each neighbour in dependence on the measured channel qualities.